Google's notable acquisitions besides Motorola

On Tuesday, Google Inc. completed its $12.5 billion deal to take over Motorola Mobility Holdings Inc. The deal is Google's largest ever — nearly four times larger than the previous high, the 2008 purchase of online advertising company DoubleClick for $3.2 billion.

It's also more than the $10.2 billion that Google has spent combined to buy nearly 200 companies since Google went public in 2004. Those companies expanded or complemented the breadth of services that the search leader offers.

Here are some notable ones:

— DoubleClick Inc. (2008). Google bought the provider of online advertising services for $3.2 billion to help it provide more dynamic, multimedia ads besides the short text links that appear next to its search results.

— YouTube Inc. (2006). Google's $1.76 billion acquisition of the online video sharing site turned out to be a good bet. The site once known mainly for pirated material and home videos of kittens has become an entertainment destination on the Internet.

— AdMob Inc. (2010). Google paid $681 million in stock to buy this mobile advertising service provider in a move to push ahead in this fast-growing market.

— ITA Software Inc. (2011). The $676 million purchase of this airline fare tracker helped Google muscle into the online travel market, though it had to make big concessions in order to clear regulatory hurdles.

— Postini Inc. (2007). Google bought the email security company for $546 million to beef up the security and storage products it offers to businesses.

— Widevine Technologies Inc. (2010). Google paid $158 million in cash for this provider of digital-rights management software, which is used to secure online video content.